1. Field of the Invention
This invention relates broadly to surgery. Particularly, this invention relates to orthopedic devices for fixation of clavicle fractures and methods of using the same.
2. State of the Art
Traditionally, orthopedic surgeons have accepted nonoperative treatment as the standard of care for fractured clavicles, likely the result of earlier studies showing unsatisfactory outcomes with operative treatment. However, recent studies show significant risks with nonoperative treatment, including chronic pain, weakness, and a higher nonunion rate. Hill, J. M., et al. “Closed Treatment of Displaced Middle-Third Fractures of the Clavicle Gives Poor Results.” Journal of Bone and Joint Surgery, May 1998: 537-539. In addition, poor operative results in the past may have been related more to the technique used than the concept of treating these fractures operatively.
Placement of plate and screws on the clavicle requires significant soft tissue stripping, which may compromise blood supply to the bone and subsequent healing. Furthermore, this treatment creates multiple stress risers in the clavicle, due to the use of several bicortical screws in the plate. Another treatment, smooth pin fixation, presents problems with possible pin migration.
The Rockwood Clavicle Pin, available from DePuy, fits into the intramedullary canal of the clavicle through a small incision over the fracture site with minimal soft tissue dissection. The device is specially designed to allow natural compression at the fracture site, minimizes hardware migration and can be easily removed under local anesthesia. This pin has a threaded end that may be screwed into the medial fragment of the fractured clavicle. The opposite end has a thread for receiving a nut that may be retained in the lateral fragment and tightened to reduce the fracture. The intramedullary placement of the Rockwood Clavicle Pin helps remedy past treatment issues, including impaired blood supply, painful, prominent hardware, and stress risers related to removal of a plate and associated screws. However, the pin may not be suitable for certain fractures, such as a non-union fracture, where compression across the fracture is undesirable.
The clavicle nail disclosed in co-owned and co-pending U.S. Pub. No. 20050065528 A1 to Orbay, includes threaded parallel holes displaced along an endosteal surface for receiving unicortical machine screws. The surgeon positions the nail inside the medial and lateral fragments of the fractured clavicle and then uses a jig attached to the nail for drilling bone holes in alignment with the threaded screw holes. Screws are inserted through the bone and thread into the nail. The unicortical screws have low-profile heads that tighten against the bone surface while compressing the nail plate against the endosteal wall of the medullary canal to maintain the reduction of the fracture.
Since the time when the application to Orbay was filed, further development has resulted in a nail and implantation method that takes full advantage of proven surgical techniques. In addition, unique structural features have been provided to the new nail that facilitate its implantation within the medullary canal of the clavicle bone and operate to stabilize a clavicle fracture.